JPH08200631A - Burner - Google Patents

Abstract

PURPOSE: To provide a burner in which burning noise due to the disorder of a wall surface flow is prevented and the deterioration of a heat exchanger is prevented. CONSTITUTION: A wall surface flow regulating structure is formed of a flow rate specifying means 35c of a wall surface flow A3 of the air rising at the surface of substantially the case inner wall inside an implement case, etc., in the case of burning, a wall surface flow diffusing means 32a arranged at the downstream of the specifying means to diffuse the wall surface flow specified at the flow rate, and a wall surface flow straightening means 32b provided at the downstream of the diffusing means to straightening the flow of the wall surface flow.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion device such as a water heater and a bath kettle, and more particularly to a combustion device having a wall surface adjusting means for raising an inner wall of the case during combustion.

[0002]

2. Description of the Related Art Conventionally, such a combustion apparatus has a combustion section having a burner unit including a plurality of burners in a case. A combustion fan for supplying combustion air is provided below the combustion unit, and a heat exchange for converting the supplied water into hot water by heat exchange is provided above the combustion unit. Bowls etc. are arranged.

[0003]

However, such a combustion apparatus has the following problems. Figure 7
Shows an enlarged part of the combustion device. In the figure, the burner unit 1 is provided with flat burners 4 and 4 such as a press burner in an aligned manner. The burner unit 1 is housed in a case 2 of the appliance.

When combustion is performed, air from a combustion fan (not shown) is sent from below, and when fuel gas is sent into each burner 4, 4, it is supplied as premixed air. Further, the air from the combustion fan rises as A1 along the inner wall of the case 2 of the combustion device to form a wall surface flow. This wall surface flow rises in the device over substantially the entire inner wall of the case 2.

Here, the wall surface flow A1 of FIG. 7 is restricted in flow rate by passing through the hole 5a formed in the baffle plate 5,
Go further up. At this time, when the wall surface flow A1 rises along the inner wall of the case 2 formed corresponding to the outer shape of the burner unit 1, the wall surface flow A1 is directed inward as shown in the drawing according to the shape of the case 2. If the wall air flow is excessive, the flame F1 blown out from the upper surface of the burner unit will be flared from the side, and if the wall flow is small as shown in FIG. The resulting Coanda effect flares the flame. This allows the flame F
No. 1 causes turbulence and becomes a source of noise.

Further, when the flame F1 agitated by the wall surface flow A1 hits the wall 3 of the heat exchanger, the wall 3 of the heat exchanger is exposed to an open flame, and the wall 3 is cracked. It was a cause of deterioration.

In view of the above points, the present invention has an object to provide a combustion device which prevents combustion noise due to turbulence of a wall surface flow and prevents deterioration of a heat exchanger.

[0008]

According to the present invention, the above object is to provide a combustion apparatus in which a combustion section having a plurality of burners is housed in a case, and when burning, substantially inside the case. A flow rate restricting means for a wall surface flow of air rising up the wall surface of the case inner wall, a wall surface flow diffusing means disposed downstream of the flow rate restricting means and diffusing the flow rate restricted wall surface flow, and a downstream side of the diffusing means. And a wall surface flow rectifying means for rectifying the flow of the wall surface flow.

In the combustion apparatus of the present invention, preferably, the plurality of burners are aligned in one direction within the housing to form a burner unit, and the burner units are provided at both ends thereof in the burner alignment direction. A wall flow adjusting means should be provided.

In the combustion apparatus of the present invention, preferably, the plurality of burners are aligned in one direction in the housing to form a burner unit, and end portions in a direction intersecting the alignment direction of the burners. In addition, the wall surface flow adjusting means is provided at the end portion on the back side with respect to the front surface of the combustion device.

Further, in the combustion apparatus of the present invention, preferably, the plurality of burners are a combination of a burner for burning rich gas and a burner for burning lean gas, so that the burners for burning all primary dark and light combustion are combined. You may make it comprise a unit.

[0012]

According to the above construction, the flow rate of the wall surface flow that has risen substantially over the inner wall of the case of the combustion device is restricted by the flow rate restricting means so as not to become an excessive wall surface flow. Then, downstream of it, a uniform wall surface flow is created by a wall flow diffusing means, and further, by a wall surface flow rectifying means, it is arranged so that it has a predetermined flow velocity and a direction that follows the flame. As a result, the air curtain with a uniform wall flow rises. As a result, the flame is maintained in an appropriate shape at the end of the burner unit of the combustion section without burning the combustion flame.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings. In addition, since the Examples described below are preferred specific examples of the present invention, various technically preferable limitations are given. However, the scope of the present invention particularly limits the present invention in the following description. The embodiment is not limited to these embodiments unless otherwise stated.

FIG. 1 shows the overall structure of a water heater as a combustion apparatus according to an embodiment to which the present invention is applied. In FIG. 1, a water heater case 21 of the water heater has a burner unit 20, a water heater combustion fan 22, a heat exchanger 24,
The nozzle holder 26 and the like are housed.

A plurality of burners are accommodated in the burner unit 20 as a combustor, as will be described later, and on the burner unit 20, a heat exchanger for converting the supplied water into hot water of a predetermined temperature. 24 are arranged. Also,
A combustion fan 22 is provided below the burner unit 20, and mainly supplies combustion air. Nozzle holder 2 facing the burner unit
6 are arranged. The nozzle holder 26 supplies fuel gas to each combustion burner of the burner unit 20 together with premixed air. In this case, the nozzle holder 26 has two types of gas nozzles 72 and 92, which correspond to the two types of burners housed in the burner unit 20 of this embodiment. The gas nozzle 72 is arranged horizontally in the drawing, and the gas nozzle 92 is arranged facing upward.

As shown in FIGS. 2 and 3, the burner unit 20 includes a plurality of burners 33 and a plurality of burners 33 in a metal container 35 which is lightweight and durable and is made of, for example, stainless steel.
34 are accommodated. That is, as schematically shown in FIG. 2, the water heater case 21 houses a metal burner case 37.
A metal housing 37, which will be described in detail later, is housed in the. The housing 37 is capable of aligning and fixing a plurality of burners 33, 34, and the burner case 3
After accommodating the accommodating body 35 in 7, the lid 37a is fixed.

As shown in FIG. 3, the burners 33 and 34 are composed of a rich burner 33 for rich combustion and a light burner 34 for lean combustion. The burner 33 is formed by pressing a sheet metal and bending it into a shape as shown in the figure.
A flame port 33a is formed on the upper surface and communicates with a fuel gas intake port 33b located below. Fuel gas intake 33
b is opened toward the lower side, and is connected to the vertical connection port 35a of the container 35 of FIG. Since the rich burner 33 is a burner of a type that burns a gas-rich air-fuel mixture of a conventional type (for example, primary air 0.3 to 0.8), it is usually necessary to supply secondary air during combustion. There is. However, in this combustion device, the secondary air required by the burner 33 is supplemented by a large amount of primary air in the burner 34.

The light burner 34, as shown,
The metal plate having a predetermined shape has a plate shape as a whole. The light burner 34 is an air rich mixture of a gas for fuel and primary air (for example, a primary air ratio of 1.4 to 1.
It is a type that burns the air-fuel mixture of 8). That is, the flame burner 34a is formed on the upper surface of the light burner 34, and the flame burner 34a and the opening 34b which is the lower fuel intake port are communicated with each other by the air-fuel mixture passage 34c. A horizontally large opening 34b, which is a fuel intake port, is connected to the horizontal connection port 53 of the container 35. And burner 3
A narrowing portion is provided in the upper part of the air-fuel mixture passage 34c of 4, and a large amount of the primary air of the fuel gas supplied is sufficiently mixed by the primary element of the flow in the narrowing portion. It is supposed to be done. As a result, the air-rich air-fuel mixture is rectified before the flame port 34a and then jetted from the flame port 34a at a high flow rate.

As shown in FIG. 4, the accommodating body 35 is a metal fixing plate that defines four sides, and has positioning claws 90 and 91 at the upper end. This positioning claw 90,
91 between the end portions 33e, 34 of the burners 33, 34
e can be sandwiched so as to be alternately arranged and held, whereby a plurality of burners 33 and 34 are aligned as shown in the plan view of FIG. As shown in FIG. 3, this container 35 is a horizontal connection port for supplying a mixture of fuel gas and air to each burner in a state where a plurality of burners 33 and 34 are accommodated as described above. It has a connection port 34a perpendicular to 53. The connection port 35a of the container 35 faces the gas mixture nozzle 92 of the nozzle holder 26 shown in FIG. Container 3
The other connection port 53 of No. 5 faces the nozzle 72 of the nozzle holder 26.

Next, the combustion principle of the combustion apparatus of this embodiment will be described. 1 to 4, this combustion device is preferably for rich and lean combustion, as explained above,
Fuel gas is supplied to the nozzle holder 26 from a fuel gas supply source (not shown) through the gas supply unit. The fuel gas is supplied from the nozzle 72 of the nozzle holder 26, and at the same time, due to the negative pressure when the fuel gas is supplied to the connection port 53 of the container 35 and the fuel gas intake port 34b having a large opening, A large amount of air-rich mixture based on the air supplied by the combustion fan 22 is supplied to the light burner 34. This mixture is in the mixture passage 34c.
Is uniformly stirred and rectified by the flame burner 34 of the light burner 34.
Eject from a at a high flow rate.

Similarly, the nozzle 92 of the nozzle holder 26
The fuel gas supplied from the exhaust gas jets upward to the fuel gas intake port 33b of the rich burner 33. The gas introduced into the fuel gas intake port 33b of the rich burner 33 is
The air from the combustion fan 22 is sucked together by negative pressure, is agitated while passing through the internal gas passage 33c, and is ejected from the flame port 33a. The air-fuel mixture ejected from the flame port 33a is a high-concentration premixed gas having a high fuel gas concentration.

Therefore, a high-temperature premixed gas high-temperature flame is formed near the flame port 33a of the rich burner 33, and a low-concentration premixed gas flame is formed near the flame port 34a of the light burner 34. In this case, the amount of the low-concentration premixed gas is larger than the amount of the high-concentration premixed gas, and a part of the primary air thereof is supplied as the secondary air when the rich burner 33 burns. As a result, the entire combustion surface of the burner unit 20 is occupied by the low temperature flame of the low-concentration premixed gas, so that clean combustion with less generation of nitrogen oxides is performed.

Here, in the combustion apparatus of this embodiment, the following structure is particularly adopted. That is, in FIG. 3, wall surface flow adjusting means is provided at both ends D2, 3 (left and right ends) of the burners 33, 34 of the burner unit 20 in the alignment direction D1. Further, in FIG. 3, the burner unit 2
With respect to the direction E1 which intersects the alignment direction of the burners of 0, the wall surface flow adjusting means is also provided on the front side E2 of FIG.
Hereinafter, each wall flow adjusting means will be described in detail.

First, the left and right sides of the burner unit 20 (D
2 and D3) will be described. FIG. 5 is an enlarged sectional view showing the wall surface flow adjusting means 60 provided on the left side of the burner unit 20, that is, on the D2 side in FIG. Since the wall flow adjusting means provided on the right side of the burner unit 20, that is, on the D3 side has a structure symmetrical to that of FIG. 5, duplicated description will be omitted. In the figure, the wall surface flow adjusting means 60 includes a wall surface flow rate regulating means 35c, a wall surface flow diffusing means 32a provided downstream of the wall surface flow, and a wall surface flow rectifying means 32b provided downstream thereof. There is.

The wall surface flow rate regulating means 35c is shown in FIG.
It is composed of a flange portion protruding from the left and right side surfaces of the container 35. A plurality of ventilation holes 35 are formed in the flange portion 35c.
d is formed. Thereby, the flange portion 35c
As shown in FIG. 2, when the housing 35 that constitutes the burner unit 20 is housed in the burner case 37, the clearance between the housing 35 and the burner case 37 that can be formed on the side surface is shown in FIG. It is supposed to be closed.

The wall surface flow diffusing means 32a and the wall surface flow rectifying means 32b are formed by a burner case 37 or a projecting portion having an inverted L-shaped cross section and provided so as to project inward. The diffusion means 32a for the wall surface flow is the burner surface 3 of the burners 33, 34.
It extends horizontally below 3a and 34a and substantially constitutes a baffle. Wall flow rectification means 32b
Is a vertical plate portion extending integrally and vertically from the inner end portion of the baffle plate 32a until reaching a position higher by L2 than the flame face 33a, 34a.

In the combustion apparatus of this embodiment, during combustion, the wall surface flow A3 is generated along the inner wall of the burner case 37.
Ascend as shown. The amount of air flowing through the wall surface flow A3 is limited by the flange portion 35c. That is, the wall surface flow A3 folds upward by 10 as much as the wall surface flow A3 passes through the ventilation hole 35d of the flange portion 35c, and the wall surface flow A3 whose flow rate is limited hits the baffle plate 32a. The wall surface flow A3 hits the baffle plate 32a. The wall surface flow A3 flows in the horizontal direction by the baffle plate 32a and then is guided so as to rise along the vertical plate portion 32b, so that this portion is substantially a narrowed portion. Therefore, the wall surface flow passing through the respective ventilation holes 35d of the flange portion 35c is diffused below the flame hole surfaces 33a and 34a of the burner,
It becomes a uniform flow. Next, the wall surface flow A3 passes through the vertical plate portion 3
By rising along 2b, it is rectified and the flow velocity increases. In this case, as shown by L2 in FIG. 5, the vertical plate portion 32b
Can regulate the fluctuation of the flame rising from the burner 33 at the end by directly rectifying the wall surface flow A3 until it reaches at least half the height of the rich flame, and hit the lower part of the wall surface 24a of the heat exchanger directly. To be prevented.

Further, when the combustion device is constructed as a rich / lean combustion device as in this embodiment, the rich burner 3 is used.
3 and the light burner 34 are arranged alternately, and the burner unit 2
The rich burner 33 is located at the end of 0. Here, when the light burner 34 is disposed adjacent to the inside of the rich burner 33, a mixture gas having a high flow velocity is jetted from the flame hole 34a of the light burner 34 as indicated by an arrow A2. On the other hand, the flow velocity of the air-fuel mixture ejected from the flame holes 33a of the rich burner 33 is relatively low. The rich burner 33 is supplied with a large amount of secondary air from the light burner 34, maintains stable combustion, and is entrained on both sides by the high flow velocity of the air-fuel mixture from the light burner 34, and the burner unit 20 as a whole. Maintains a uniform burning flame. It should be noted that the burners 33 and 34 are hermetically sealed and there is no rising air.

Therefore, looking at the rich burner 33 arranged at the end of the burner unit 20, in FIG. 5, an adjoining light burner 34 is arranged on the left side of this rich burner 33, but on the right side thereof. do not do. For this reason, the flame of the rich burner 33 receives the shortage of air from the lean premixed air of the left light burner 34, is pulled by the high flow velocity of the air-fuel mixture, and tends to be entrained in the flame. Further, as shown in FIG. 7 and FIG. 8, rich flame enters into the lean flame due to the amount of wall flow and rectification, or flapping phenomenon occurs between the lean flame side and the heat exchanger wall. For this reason, the flame of the rich burner 33 is drawn to the fast flow velocity of the light burner 34 only on the left side, and the flow field is unbalanced on the right side, causing fluctuations and flapping of the flame, which causes noise. . However, as shown in FIG. 5, in this embodiment, as described above, the wall surface flow A3 has a high flow velocity because it is rectified and rises, so that the flow velocity on the right side of the burner 33 is accelerated to the side adjacent to the light burner. It is possible to create a flow field in a situation close to that of (1), and it is possible to balance it with the left side where the light burner 34 is provided when the rich burners arranged at both ends are also supplied with appropriate secondary air. As a result, the flame F2 having a stable height and shape can be obtained even at the end portion of the burner unit 20, and the rectified combustion is favorably performed, and the generation of noise can be effectively prevented.

FIG. 6 shows the rear side of the burner unit 20 (E
2 shows a wall flow adjusting means 61 provided in 2).
In the figure, the flow rate adjusting means 3 is provided on the back side of the container 35.
6 is provided. In the present embodiment, the flow rate adjusting means 36 is a metal plate attached to the back surface of the container 35, and the flange portion 3 having a rectangular cross section is provided at the lower part thereof.
6c is formed along substantially the entire length of the container 35 in the longitudinal direction. An elastic body, for example, packing 36a is arranged on the back side of the flange portion 36c. by this,
As shown in the arrow of FIG.
When it is housed in, the gap between the inner wall of the burner case 37 and the housing 35 can be completely sealed. Further, the ventilation hole 36 is formed in the flange portion 36c.
b and 36b are formed.

The upper portion of the flow rate adjusting means 36 is extended upward, and the upper end portion 36d is folded back inward so that the end portion 3 of each of the burners 33, 34 constituting the burner unit 20 is formed.
The upper surfaces of 3e and 34e are locked. As a result, the flow rate adjusting means 36 causes the plurality of burners 33, 34 to
Also serves as a locking piece to prevent the falling off. Further, the container 3
A baffle plate 38 extending rearward (toward the left side in FIG. 5) is provided on the rear surface side of 5. The baffle plate 38 is located below the flame hole surfaces 33a and 34a of the burners 33 and 34, and a gap S1 is formed between the tip of the baffle plate 38 and the inner wall of the burner case 37. Further, an inclined plate 39 is provided at the upper end of the burner case 37, and is inclined upward inward from above the baffle plate 38 to the height of the flame F3. The inclined plate 39 serves as a rectifying means. Has become.

The wall surface flow adjusting means 61 of this embodiment is constructed as described above, and when the combustion device burns, the wall surface flow A4 of air rises along the inner wall of the burner case 37. The wall surface flow A4 hits the flange portion 36, and a part of the wall surface flow A4 is passed through the ventilation holes 36b, 36b, so that the flow rate is limited. This suppresses an excessive rise in the wall surface flow. Next, the wall surface flow A4 further rises,
A gap S1 formed between the baffle plate 38 and the inner wall of the burner case 37
Though S1 becomes a narrowing part, and the wall surface flow A4
Are evenly spread. Furthermore, this diffused wall surface flow A
4, the flow velocity is increased while being guided inward in FIG. 6 by the inclined plate 39 as the rectifying means. by this,
The combustion flame F3 from the flame holes 33a, 34a of the burners 33, 34 is prevented from extending outward from the burner unit 20 as shown by the chain line, and is formed vertically at a predetermined height as shown by the solid line. The flame is kept as it is.

That is, the combustion flame F3 is contained in the container 3 during combustion.
Since flapping of the flaming material 5 is prevented, the generation of noise accompanying this is effectively prevented. Furthermore, the combustion flame F3 and the lower part of the wall surface 2 of the heat exchanger are directed diagonally inward of the burner unit 20 by the wall surface flow A4.
A layer of air is formed in a curtain shape between itself and 4a. This prevents the wall surface of the heat exchanger from being directly exposed to the flame and effectively prevents the occurrence of cracks.

In the above-mentioned embodiment, the combustion device for performing the density combustion is explained, but the present invention is not limited to the density combustion device and the water heater, but is applied to all the combustion devices which generate a wall flow. Further, in the above-described embodiment, the wall flow is described as rising on the inner wall of the burner case. However, when forming the burner unit without using the burner case, the wall surface rising on the inner wall of the instrument case is used. As a matter of course, the above adjusting means may be provided for the flow.

[0035]

As described above, according to the present invention, it is possible to provide the combustion device which prevents the combustion noise due to the turbulence of the wall surface flow and prevents the deterioration of the heat exchanger.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing the overall structure of an embodiment of a combustion apparatus according to the present invention.

FIG. 2 is a schematic diagram showing a configuration of a combustion section of the combustion device of FIG.

FIG. 3 is a schematic perspective view showing a configuration of a burner unit of the combustion apparatus of FIG.

FIG. 4 is a schematic plan view showing a configuration of a burner unit of the combustion apparatus of FIG.

5 is an enlarged sectional view of an essential part showing an embodiment of a wall surface flow adjusting means applied to the combustion apparatus of FIG.

6 is an enlarged cross-sectional view of a main part showing another embodiment of the wall surface flow adjusting means applied to the combustion apparatus of FIG.

FIG. 7 is an explanatory diagram showing a comparative example of the wall surface flow of the combustion device.

FIG. 8 is an explanatory diagram showing a comparative example of the wall surface flow of the combustion device.

[Explanation of symbols]

 21 Instrument Case 22 Combustion Fan 24 Heat Exchanger 26 Nozzle Holder 32a Wall Surface Flow Diffusing Means 32b Wall Surface Flow Rectifying Means 33 Thick Burner 34 Light Burner 35 Container 35c Flow Rate Adjusting Means 36 Wall Flow Diffusing Means 37 Burner Case 38 Baffle Plates 60, 61 Wall flow adjustment means

Claims (4)

[Claims] 1. A combustion apparatus in which a combustion unit having a plurality of burners is housed in a case, wherein a wall surface flow of air that rises substantially inside the case inside the case during combustion is used. Flow rate regulating means, wall surface flow diffusing means disposed downstream of the flow rate regulating means and diffusing the flow rate regulated wall surface flow, and wall surface flow rectifying provided downstream of the diffusing means and rectifying the flow of the wall surface flow And a wall surface flow adjusting structure including a means. 2. The plurality of burners are aligned in one direction in a housing to form a burner unit, and the wall surface flow adjusting means is provided at both ends of the burner unit in the burner alignment direction. The combustion device according to claim 1. 3. The plurality of burners are aligned in one direction in a housing to form a burner unit, and are end portions in a direction intersecting the alignment direction of the burners,
The combustion apparatus according to claim 1, wherein the wall surface flow adjusting means is provided at an end portion on the back side of the front surface of the combustion apparatus. 4. The burner unit for all primary rich / lean combustion is configured by combining a burner for rich gas combustion and a burner for lean gas combustion, as the plurality of burners. The combustion device according to 1.